Refrigerator cabinet construction



Feb. 19, 1963 K. K. KESLING REFRIGERATOR CABINET CONSTRUCTION 2Sheets-Sheet 1 Filed July 25. 1960 jumvrm Keith K Kes/ing Fig.

Feb. 19, 1963 K. K. KESLING REFRIGERATOR CABINET CONSTRUCTION 2Sheets-Sheet 2 Filed July 25, 1960 R o 0. mm W m e o K K WA mm 6 a K20B} use Fig. 7 0:

United states Patent 3,078,t3i 3 REFRIGERATQR CABINET CUNSTRUC'HQN KeithK. Kesling, Dayton, Ohio, assignor to General Motors Corporation,Detroit, Mich, a corporation of Delaware Fiied July 25, 1%0, Ser. No.44,959 3 Claims. (Cl. 220-9) This invention relates to cabinets andparticularly to the construction of wall sections for refrigeratorcabinets having a plastic insulating material foamed into the spacebetween outer panels of the sections.

Some modifications of the new foamed-in-place polyurethanes haveinsulation characteristics sufficient to make possible low-cost,thin-walled refrigerator cabinets having lower heat leakage than formerthick-Walled cabinets which were insulated with glass wool or mineralwool. It is commonly known that these new foamed polyurethanes haveexcellent adhesion properties, are light in weight, high in structuralstrength for their weight and are good insulators. However, fulladvantage of these properties cannot be realized by merely fillinginsulation spaces between panels of cabinet wall sections with these orother equivalent foamed materials because this alone does not render theuse of such insulation practical. polyurethane are so great that itfirmly bonds two Opposed wall or panel members of wall sections of arefrigerator cabinet to such a degree as to prevent separation of onepanel from another without damaging the members beyond repair orcracking or breaking the polyurethane insulation therebetween. Suchpanel or wall members in wall construction or sections, particularly ofrefrigerator cabinets, occassionally become damaged and requirereplacement. This replacement cannot be accomplished if polyurethane isfoamed directly between these panels because it firmly bonds to eachpanel and prevents their separation. Obviously, therefore,foamed-in-place polyurethane insulation material between opposed wallsor panels of wall sections presents a problem in the refrigeratorcabinet construction art. I contemplate to take advantage of theproperties of foamed polyurethane in sulation to a substantial degree inthe construction of insulated wall sections for refrigerator and othersimilar cabinets to overcome the problem just stated and to thereby atthe same time derive other advantages therefrom.

An object of my invention is to provide for the separation of one wallor panel from another thereof in a wall section or main body portion ofa cabinet irrespective of the type of insulating material confined in aspace between the walls or panels.

3,ll78,0il3 Patented Feb. 19, 1953 tinuous sheet of material, to whichpolyurethane will not adhere or bond, over a first portion of a wall orpanel of a wall section of a refrigerator cabinet so that the other orsecond portion of such wall or panel of the wall section can, upon beingdamaged, be easily removed from the first portion and readily replacedwith a new one, when desired.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being bad to the accompanyingdrawings wherein preferred embodiments of the present invention areclearly shown.

, shown in open position;

For example, adhesion properties of foamed Another object of myinvention is to provide a divider thane insulating material foamed inplace between walls or panels thereof with means in the section or bodyportion to prevent adhesion or bonding of this foamed material to bothwalls or panels whereby one wall or panel can be readily separated fromthe other.

A still further object of my invention is to provide for the separationof one wall or panel of a wall section or a main body portion of arefrigerator cabinet from another thereof having foamed polyurethaneinsulation therebetween without damaging parts of the section or FIGURE2 is an enlarged fragmentary broken sectiona1 view taken along the lines2-2 of FIGURE 1 showing a cabinet wall section having my inventionembodied therein;

FIGURE 3 is a view similar to FIGURE 2 and shows the cabinet linermember moved part way out of the cabinet wall structure;

FIGURE 4 is an enlarged fragmentary sectional view taken along the lines4-4 of FIGURE 1 showing an edge portion of the refrigerator cabinet doorhaving a gasket thereon;

FIGURE 5 is an enlarged perspective view partly in section of therefrigerator cabinet door to illustrate my invention;

FIGURE 6 is a view similar to FIGURE 5 showing a modified refrigeratorcabinet door structure; and

FIGURE 7 is a view similar to FIGURE 5 and 6 showing another modifiedrefrigerator cabinet door structure.

Referring now to the drawings, for illustrating my invention, I show inFIGURE 1 thereof ahousehold refrigerator cabinet, 10 having a pluralityof insulated walls or wall sections defining a food storage chamber 11therein. Chamber 11 has a plurality of food supporting shelves 12mounted therein and this chamber is adapted to be cooled by anevaporator of a refrigerator system associated with cabinet 10 whichevaporator is prefer ably of the pressure welded sheet metal type and ismounted in the upper part of chamber 11 behind a movable closure member13 therefor as is conventional in the art. An opening in the front ofcabinet 10 provides access to chamber 11 and this opening is normallyclosed by an insulated door structure or wall section generallyrepresented at 15 which is hingedly mounted on cabinet It) by suitablehinges for horizontal swinging movement relative thereto. The insulatedwall section or door structure 15 comprises (see FIGURE 4) an outermetal panlike member 16, an inner molded plastic panel member 17, whichmay be dished or recessed inwardly for accommodating the mounting ofdoor shelves thereon, and means other than insulation 18 between themembers 16 and 17 for detachably securing them together. Door 15 alsocomprises a thin flexible nonmetallic sheet 19 intermediate the doormembers 16 and 17 and extending over the insulation 18 to provide adivider in the door or Wall section for a purpose to be hereinafter morefully described. Outer pan-like members 16 of door or wall section 15has an inwardly bent flange 21 about the periphery thereof which isprovided with internally threaded extrusions 22 forming tapped holes forreceiving screws 23 to secure edges of members 16 and 17 together. Thesecuring means or screws 23 pass through suitable holes provided nearthe edge of panel member 17 and in a lip or flanged portion of arubber-like resilient gasket 24 whereby to secure the members 16 and 17to one another, as well as to clamp gasket 24 on the door structure orinsulated wall section 15.

Other insulated wall sections of cabinet 14) comprise an outer invertedsubstantially U-shaped sheet metal shelllike member 26 (see FlGURE 2)forming the exterior top and side surfaces of the cabinet and an innermetal box-like member or liner 27, spaced from member 26 forming wallsof chamber 11. The inner surfaces of liner member 27 are preferablycoated with porcelain enamel as is the practice in the art to render theinterior of food chamber 11 readily cleanable. Insulating material 28,similar to the insulation 18 in door 15, is located between members 26and 27 and substantially fills the space therebetween. A thin fiexilenonmetallic bag or sheet 29 is disposed intermediate members 26 and 27and lies over the insulation 28 in contact with liner member 27. Thiswall section of the main body portion of cabinet also includesnonmetallic preferably molded plastic breaker strips 31 having a groovedinner edge overlapping the front edge portion of liner member 27 andhaving its outer edge fitted in a channel 32 formed in an inturned frontportion 33 of shell 26. The breaker strips 31 extend around the throatof opening to chamber 11 and are detachably locked in place at cornersof this opening by suitable gusset plates removably attached to cabinet10 in any conventional manner now well known to those skilled in theart. Such removable gusset plates, together with the strips 31, formmeans for securing the forward edge part of liner member 27 to the frontpart of shell member 26. The fiat forward portion 33 of outer shellmember 26 about the front of cabinet 10 provides a door jamb on thecabinet which is adapted to be abutted by gasket 24 on door for sealingthe access opening of chamber 11. It is to be noted that bag or sheet 29extends continuously along the inner surface of liner member 27 andbreaker strips 31 to prevent bondage of the insulation to these elementsand to thereby serve a purpose to be hereinafter described.

'In accordance with my invention it is desired to take advantage of theinherent properties or characteristics of a foamed plastic insulationwhereby substantially lightweight insulated wall structures or sectionscan be made thinner and of increased structural strength while, at thesame time, providing for the separation of certain elements in suchstructures or sections. For this reason I utilize a foamed-in-placepolyurethane insulating material in combination With a thin sheet ofpolyethylene material to which such insulation does not adhere toaccomplish the objects of my invention, as hereinbefore set forth, andto obtain other advantages. To this end it should be understood thatdifferent arrangements may be employed in the application of foamedpolyurethane insulating material to wall structures or sections of acabinet and thus I do not wish to be restricted to a specificapplication of the insulation to one or the other members of a wallsection. For example, one member of a wall section to which thepolyurethane insulation is to be foamed and bonded may be placed in amold construction of. such material that the insulation will not adhereor bond thereto or the mold may be inserted into the body portion of arefrigerator cabinet. In either event there will be a space between theone member of the wall section and walls of the mold to be substantiallyfilled by foaming the polyurethane insulation thereinto. After thisinsulation has been foamed in place and bonded to the one member of awall structure or section, the nonadhering mold may be removed to permitassembly of other elements of the structure or section thereto.Conversely or on the other hand all elements of the wall structure orsection may be assembled to one another with a thin flexible bag orsheet of polyethylene material added into the structure or wall sectionalong surfaces of certain elements thereof to which the polyurethaneinsulation will not bond and then this insulation is foamed in the spacebetween wall members of the completely assembled section or structure.Thus, it should be apparent that either of these alternative methadswill suffice to accomplish the novelty of the present disclosure whichis that of permitting one wall part or member to be separated andremoved from another wall part or member of a wall section havingplastic insulation foamed into the space between the members and bondedto at least one of them.

Referring now again to FIGURE 2 of the drawings, it will be noted thatthe polyethylene sheet 29 extends over the foamed polyurethaneinsulation 28 bonded to member 26 and along the inner surface ofelements or parts of the cabinet wall section to be removed therefrom,if desired or required, and provides a divider between portions thereofto prevent bondage of the insulation thereto. The divider sheet 29 isimpervious to air and moisture and provides a point of separation ofwall members of the cabinet wall structure or section. Should theporcelain enamel coated metal liner member 27 become scratched, marred,chipped or damaged, it may be removed from cabinet 10, particularly fromthe foamed insulation 28 and divider sheet 29, and replaced by a newliner member. In order to remove the procelain coated liner member 27,the corner gusset plates holding the breaker strips 31 locked in placeare first removed from cabinet 10 and then each of the strips 31 aredetached from the wall section by sliding the edge part thereof, with aspecial tool, out of a channel 32 and slipping their other edge partaway from the forward edge of liner 27 Since the polyethylene sheet 29extends beyond liner member 27 over the inner surfaces of braker strips31, the foamed insulation 28 is not bonded or adhered thereto and theirremoval is no problem. With these detachable securing means removed andsince the polyethylene sheet 29 has prevented adhesion or bondage of thefoamed polyurethane insulating material 28 to box-like liner member 27,this member may be pulled or slid outwardly from cabinet 10 in astraight-line direction paralleling the cabinet Wall section away fromthe foamed insulation 28 and shell member 26 to which the insulation isbonded (see FIGURE 3) to cause separation of the members of the wallsection and removal of the damaged liner member 27 from the cabinet. Anew porcelain enameled metal liner member 27 may be installed intocabinet 10 by reversing the operation of detaching the breaker strips 31and the corner gussets The principle of separating one wall or panelmember from another thereof in a cabinet wall section in which a foamedpolyurethane insulating material is located between the members may alsobe adopted in the construction of the refrigerator cabinet door 15.Referring now to FIGURE 5 of the drawings I show a form of a door usedon cabinet 10 wherein the metal pan-like outer member 16, together witha polyurethane insulation 18 foamed thereinto and bonded to its innersurfaces, has been removed from a mold in which the foaming of theinsulation took place. In this form of door, the contour of the innerface of the insulation has been predetermined by the mold and a sheet 19of polyethylene is placed over the face of insulation 18 to conform toits contour. The inner molded plastic panel member 17 is placed oversheet 19 and then the gasket 24 and detachable screws 23 are assembledto the door to secure the members 16 and 17 to one another so as tocomplete this cabinet wall section. If door panel member 17 becomesdamaged in any manner it can, by virtue of sheet 19 forming a dividingpoint in the wall structure, be removed from pan member 16 and thefoamed polyurethane insulation 18 bonded thereto to thereby separate themembers 16 and 17 from one another. Panel-like member 17 is separablefrom the wall section along the polyethylene sheet 19, by removing thedetachable securing means or screws 23, without disturbing, breaking ordamaging the foam insulation 18, and a new panel member can therefore bereadily replaced onto the wall section upon reattaching the screws.

In FIGURE 6 of the drawings 1 show a modified form of door at A whereinthe pan-like outer member 16A, together with a polyurethane insulation18A foamed therein and bonded to its inner surfaces to increase thestructural strength of this part of the door or wall section has beenremoved from a mold in which the foaming of the insulation took place.In this modified wall section or door structure 15A the thickness of thefoamed insulation 18A has been predetermined by walls of the mold and isflat and substantially flush'with the inturned flange 21A on door member16A. A polyethylene sheet 19A is placed over the fiat surface of thefoamed polyurethane insulation 18A and then the inner molded plasticpanellike member 17A together with any suitable or desirable insulatingmaterial 28A, filling the cavities or recesses thereof and conforming tothe fiat surfaces of the foam insulation, is placed over the structure.Thereafter the gasket 24 and detachable screws 23 are applied to thestructure to removably secure elements of the door together. It is to beunderstood that in this modification the insulation 18A and 20A may beof different materials or they may be of like material such, forexample, as the insulation 20A being polyurethane foamed into the innermolded plastic panel 17A. The polyethylene sheet 19A provides a divideror parting medium in wall or door structure 15A intermediate the members16A and 17A. Should eitherv of the members 16A or 17A be damaged andrequire replacement, it can be separated or removed from the othermember along or at sheet 19A by removing the detachable securing meansor screws 23 from this modified wall section or door structure.

I show in FIGURE 7 of the drawings a further modified form of cabinetinsulated wall'section or door structure 158 in which the section hasits structural strength increased by a still different arrangement offoamed-in-place polyurethane insulation and wherein the outer metal panmember 16B is removable from the inner molded pastic door panel 173 andfrom the insulation 1813. In this modification the polyurethaneinsulating material may be foamed into the inner panel member 17B withina suitable mold and built up to the thickness desired therein so as toprovide inclined edges protruding outwardly of member 17B. Filler strips203 having tapered sides substantially conforming to the inclined edgesof the insulation 18B are placed in door pan 16B along the sides thereofbelow flanges 21B thereon. The strips 20B can be of any suitable ordesirable nonmetallic material of moderate insulating quality. Afterinserting strips 208 into pan member 16B, a thin sheet of polyethylene19B is depressed against the flat inner face of member 16B and extendedalong the tapered sides of the inserted strips. Thereafter the innerpanel member 1713, together with the layer of insulation 18B thereon andbonded thereto, is placed over the pan member and lowered so that theinclined side edges of the insulation 18B, protruding outwardly awayfrom the inner panel 17B, snugly register with the polyethylene sheetalong bounding strips 201-3. The elements or members of this wallsection or door structure 15B are then secured together by the securingmeans or detachable screws 23. In this modified construction either wallor panel member 1613 or 17B are selectively separable and removable fromone another and particularly outer pan member 163 with its inserts orstrips 20B is removable from the insulation 183 by detaching thedetachable screws 23.

From the foregoing it should be apparent that I have provided improvedcabinet wall sections and door structures by utilizing foam plasticinsulation therein to increase the structural strength thereof while atthe same time providing a divider between portions or members of thesections or structures to one of which the strengthening insulation maybe firmly bonded for permitting separation of the members. In addition,my invention presents several advantages in the use of foamedpolyurethane insulating material in cabinet wall sections, particularlyin conjunction with a polyethylene divider sheet in such sections. Forexample, the Freon" constituent or agent used as the medium to foam aplastic insulation such as polyurethane continues to be emittedtherefrom for quite some time after the insulation is foamed in place.It is known that this Freon attacks and deteriorates other moldedplastic members or elements, particularly those formed of polystyreneand similar compounds. Since polyethylene bags or sheets are imperviousto moisture and gases, the use of such bags or sheets in the mannerherein disclosed is highly advantageous. By covering certain plasticelements or members molded of polystyrene compounds, such as the cabinetbreaker strips 31 and the molded plastic innerdoor panel member 17 witha layer of polyethylene material, these elements or members are isolatedfrom the foamed polyurethane plastic insulation 18 and 28. Thepolyethylene sheets 19 and 29 form an impervious barrier between theinsulation 18 and 28 and the elements or members 17 and 31 and theseelements or members are consequently protected against Freon emittedfrom the polyurethane insulation. This protection is unique in that itpreserves the elements or members 17 and 31 and prolongs the lifethereof. In reality, the use of polyethylene bags or sheets as hereindisclosed therefore serves a two-fold purpose in the construction ofcabinet wall sections and cabinet door sections or structures byproviding a divider therein to which the polyurethane insulation willnot adhere for permitting separation or removal of members of thesesections or structures from one another and of protecting other moldedplastic elements or members included in their construction.

While the embodiments of the present invention as herein disclosedconstitute preferred forms, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. A cabinet construction comprising, an outer shell member, a box-likeliner member nested substantially within said shell member each havingcoextensive surfaces disposed in spaced-apart face-to-face relationshipwith insulation foamed into the space therebetween, said members havingjuxtapositioned preformed peripheral edge portions, said cabinetconstruction also comprising a divider layer of material extendingbetween said peripheral edge portions and continuously over the innerface surface of said liner member adjacent the insulation preventingsame from bonding to said liner member or said peripheral edge portionswhereby said insulation bonds only to said outer shell member, saidouter shell member and the insulation bonded thereto forming aninseparable permanent component of said cabinet construction cradlingsaid box-like liner member, said box-like liner member defining Walls ofa chamber in said cabinet having an access opening, and means interposedbetween said peripheral edge portions and removably interconnected withthe preforming thereof for locking said liner member within said shellmember, said unbonded box-like liner member being removable as a unitalong said divider layer from said cabinet construction withoutfracturing the insulation of said permanent component thereof when saidlocking means is removed.

2. A cabinet construction comprising, an outer shell member, a box-likeliner member nested substantially within said shell member each havingcoextensive surfaces disposed in spaced-apart face-to-face relationshipfrom juxtapositioned peripheral edges with insulation foamed into thespace therebetween, said cabinet construction also comprising a dividerlayer of material extending continuously over the inner face surface ofone of said members adjacent the insulation preventing same from bondingthereto whereby said insulation bonds only to the other of said members,said other member and the insulation bonded thereto forming aninseparable permanent component of said cabinet construction cradlingsaid box-like liner member, said box-like liner member defining walls ofa chamber in said cabinet having an access opening, and means interposedbetween said members for locking said liner member within said shellmember, said one unbonded member being removable as a unit along saiddivider layer from said cabinet construction without fracturing theinsulation of said permanent component thereof when said locking meansis ineffective to lock said liner member within said shell member.

3. A separable double walled cabinet structure compris- (a) an innerside member and an outer sheet metal side member providing opposed sidesof said structure each having long wide coextensive surfaces directedinwardly of the double walled structure from juxtapositioned peripheraledges of said member,

(11) an edging part of said outer metal side member being flangedlaterally thereof to provide an integral wall portion thereon boundingsaid double walled structure in the vicinity of said juxtapositionededges of the members,

(c) the surfaces of said side members extending in spaced apartsubstantially parallel face-to-face relationship and having insulationfoamed into the space therebetween,

(d) a layer of material to which the foamed insulation will not adheredisposed over said insulation inter-mediate same and one of saidsidemembers of the double walled structure providing a separatortherein,

(e) said layer extending continuously along the inner face of said oneside member throughout the length and Width of its long wide surface andoverlapping said peripheral edge of the other of said side members ofsaid double Walled structure,

(f) said separator preventing bonding of said insulation to said oneside member whereby the insulation bonds only to the long wide innerface of said other side member paralleling the one side member andrendering said one unbonded member capable of removal from thestructure,

(g) said other side member and the insulation bonded thereto forming aninseparable permanent component of said double walled structure forincreasing its rigidity when the unbonded side member thereof is removedtherefrom,

(11) means other than said insulation detachably interlocking edges ofsaid one unbonded side member to said other member of the inseparablecomponent of said double walled structure adjacent said integralbounding wall on said metal member'thereof, and

(i) the one unbonded side member of said double walled structure beingupon detaching said detachable means removable at said separator fromsaid other side member thereof without fracturing the insulation on saidpermanent component of the structure.

References Cited in the tile of this patent UNITED STATES PATENTS2,106,840 Gould Feb. 1, 1938 2,552,641 Morrison May 15, 1951 2,629,698Sterling Feb. 24, 1953 2,723,896 Wurtz Nov. 15, 1955 2,895,603 FreemanJuly 21, 1959 2,958,210 Rill Nov. 1, 1960

2. A CABINET CONSTRUCTION COMPRISING, AN OUTER SHELL MEMBER, A BOX-LIKE LINER MEMBER NESTED SUBSTANTIALLY WITHIN SAID SHELL MEMBER EACH HAVING COEXTENSIVE SURFACES DISPOSED IN SPACED-APART FACE-TO-FACE RELATIONSHIP FROM JUXTAPOSITIONED PERIPHERAL EDGES WITH INSULATION FOAMED INTO THE SPACE THEREBETWEEN, SAID CABINET CONSTRUCTION ALSO COMPRISING A DIVIDER LAYER OF MATERIAL EXTENDING CONTINUOUSLY OVER THE INNER FACE SURFACE OF ONE OF SAID MEMBERS ADJACENT THE INSULATION PREVENTING SAME FROM BONDING THERETO WHEREBY SAID INSULATION BONDS ONLY TO THE OTHER OF SAID MEMBERS, SAID OTHER MEMBER AND THE INSULATION BONDED THERETO FORMING AN INSEPARABLE PERMANENT COMPONENT OF SAID CABINET CONSTRUCTION CRADLING SAID BOX-LIKE LINER MEMBER, SAID BOX-LIKE LINER MEMBER DEFINING WALLS OF A CHAMBER IN SAID CABINET HAVING AN ACCESS OPENING, AND MEANS INTERPOSED BETWEEN SAID MEMBERS FOR LOCKING SAID LINER MEMBER WITHIN SAID SHELL MEMBER, SAID ONE UNBONDED MEMBER BEING REMOVABLE AS A UNIT ALONG SAID DIVIDER LAYER FROM SAID CABINET CONSTRUCTION WITHOUT FRACTURING THE INSULATION OF SAID PERMANENT COMPONENT THEREOF WHEN SAID LOCKING MEANS IS INEFFECTIVE TO LOCK SAID LINER MEMBER WITHIN SAID SHELL MEMBER. 